The singer tied the knot with the illustrator in an intimate ceremony attended by close friends and family last Friday (2 January).
The nuptials were followed by a huge party the following evening at the stately home Aynhoe Park in the Cotswolds.
Guests, including Gary Barlow, Mark Owen and former Take That bandmate Jason Orange, sipped champers and tucked into pizza and fish and chips at the bash.
"Everyone is so chuffed for Howard and Katie. They make a gorgeous couple.”
Howard, 46, has been dating Katie since 2010, after they met when Take That filmed the 2008 Marks & Spencer Christmas TV advert.
A guest said: “Howard looked extremely happy with his bride Katie at his side amongst their guests. There were about 140 people there – it was a kicking do until at least 1.30am”
Congrats to them both!